Computer controlled robots are being increasingly employed in the manufacturing and fabrication arts. Robots are widely used for welding, drilling, sawing and other manufacturing and fabricating techniques.
Index tables are used as supports for work pieces wherein work pieces mounted upon the table surface are indexed between stations wherein sequential machining or working operations occur. With the advent of computerized robots, index tables have also been used in conjunction with robots mounted adjacent the index table wherein the robot controlled apparatus works upon work pieces mounted upon an index table. However, in such combination index table/robot installations extensive space requirements are necessary and relatively complicated robot movements are necessitated as the work rotates between various positions due to the index table rotation.
It is an object of the invention to provide a combination index table and computer controlled robot assembly wherein the robot is mounted upon a column coaxial with the index table axis of rotation, and the robot is capable of accessing the entire work supporting table surface.
Another object of the invention is to provide a combination index table and computerized robot wherein the robot acts upon work pieces located on the table support surface wherein the entire assembly is of a concise configuration occupying minimal floor space.
Yet another object of the invention is to provide a combination index table and computerized robot wherein the robot is mounted upon a column coaxial with the table axis of rotation, and is rotatably mounted upon the column, and wherein both the table movement and the robotic movements are computerized and programmed from a common source.
An additional object of the invention is to provide combination index table and computer controlled robot wherein high speed operations on a work piece located on the index table support surface are achieved with maximum accuracy and minimal robot movement.
In the practice of the invention the index table includes a base upon which an indexable table is mounted rotating about an axis of rotation, which is usually vertically oriented. The base includes conventional rotary and trust bearings to permit rotation of the table about its axis, and an electric motor rotates the table which may be precisely held at indexed locations by well known indexing detent devices.
The center of the index table is provided with a circular opening concentric to the axis of rotation through which a cylindrical column extends which is firmly affixed to the base. A collar is rotatably mounted upon the upper end of the column, and a robotic apparatus for working on work pieces is mounted upon the collar. The robot usually consists of a plurality of hinged arms employing servo motors for changing the angular position of the arms, and the outermost arm includes the tool or fabricating apparatus such as a welder, drill, cutting tool, or the like. The particular form of the robot mounted upon the column does not constitute an aspect of the present invention. The robot is controlled by conventional programmed computerized equipment wherein the robot may be readily programmed to perform a plurality of sequential operations on work pieces located in fixtures on the index table surface.
Rotation of the index table is through an electric motor also connected to the computerized apparatus whereby both the robotic movement and the rotation of the index table can be synchronized and correlated. Sensors sensing the rotative position of the index table work supporting surface also provide information to the computerized control, wherein the operation of the robot and index table may be accurately programmed to move the work pieces through a plurality of stations or movements, and simultaneously, move the robot tool through the desired path and program.
As both the index table and the robot are capable of substantially 360.degree. rotation about the table axis of rotation a plurality of work stations may be defined upon the index table work supporting surface permitting work to be located on and removed from jigs and fixtures mounted upon the table work surface, and the rotative movement of the robot may be correlated to the index movement wherein operations occurring on the work piece can be correlated to the work piece position to most effectively account for time.
As the robot is centrally mounted with respect to the index table no additional floor space is required for the robot support, and the robot may be rotated relative to its supporting column substantially through a complete revolution wherein the robot may follow the work piece throughout its index table movement.
Apparatus constructed in accord with the invention is of a concise configuration minimizing the floor space required for apparatus of this type, costs are reduced, and the time for performing operations on the work piece may be reduced in view the more efficient path of travel between the index table, work piece and robot.